川西北高寒草甸蚁丘植物群落演替：种类组成与物种多样性

蚂蚁通过构建蚁丘,提高了群落生境异质性,影响群落物种组成,甚至生态系统结构和功能。我们在川西北典型高寒草甸调查了平地（非蚁丘,即距离蚁丘4～5m的草地）和不同大小广布弓背蚁（Cam-ponotus herculeanus）蚁丘（小蚁丘、中蚁丘和大蚁丘3种,平均面积大小分别为309．45cm^2、948．45cm^2、2124．90cm^2）上的植物种类组成、物种多样性,以及每个物种的高度,盖度和多度,在此基础上分析了蚁丘植物群落演替进程中的优势种变迁及其机制。调查发现,与平地相比,天气晴朗条件下蚁丘的土壤温度在白天较高,而在夜晚较低,日变化的波动性较大;蚁丘中心的相对湿度低于边缘,更低于平地。群落结构分析表明,不同大小蚁丘之间植物物种丰富度和多样性差异不显著,但是优势种变化明显。随蚁丘增大,钩状嵩草（Kobresia uncinoides）的群落地位（重要值）逐渐上升,小、中、大蚁丘上的次优种分别为拉拉藤（Galium aparine）、羊茅（Festuca ovina）、垂穗披碱草（Elymus nutans）。蚁丘上禾草类优势度显著高于平地,而杂草类优势度则显著低于平地。平地上菊科（Compositae）和毛莨科（Ranunculaceae）植物占优势,蚁丘上莎草科（Cyperaceae）和禾本科（Gramineae）植物占优势。文中还讨论了蚁丘植物群落演替的可能机制,以及蚁丘对整个草甸群落组成和动态的潜在意义。     

The roles of seed mass and persistent seed banks in gap colonisation in grassland

Gaps in grassland created by animals are often sites for species regeneration. The persistent seed banks of ant-hills and surrounding soils in a calcareous grassland in southern Britain were compared and analysed in terms of seed mass and longevity. The relative abundance of species on ant-hills compared to the pasture was highly correlated with seed abundance in ant-hill soil. The abundance of plant species on ant-hills compared to the pasture was significantly negatively correlated with seed mass, and positively correlated with seed longevity. These results suggest that germination from the seed bank in ant-hill soils, as well as limited seed dispersal and vegetative invasion, contributes to the distinctive ant-hill vegetation. The same may apply to other gaps created by animals in grasslands.     

Soil pH and species diversity in coastal dunes

Soil pH was measured at two different spatial scales in coastal dunes on Norderney, North Sea, and in Mecklenburg-Vorpommern, Baltic Sea, Germany. Relationships between the variability in soil pH, species richness and species diversity are presented. Species richness and diversity were highest in grey dunes, where soil pH was at intermediate levels; both variables were lower in yellow and brown dunes. The variability in pH increased with increasing species diversity and also with scale. Overall, soil pH variability decreased with increasing vegetation cover. The lowest pH heterogeneity was found in heath dominated by Empetrum nigrum L. and grey dunes dominated by Campylopus introflexus (Hedw.) Brid. Increasing abundance of dominant species and decreasing species diversity of vegetation apparently reduces soil heterogeneity. Decreasing species diversity of vegetation is likely to explain decreasing variability in soil pH.     

The Effect of Hill-Building Activities of Ants on the Species Diversity of Plant Communitiesin Songnen Grassland 蚂蚁筑丘活动对松嫩草地植物群落多样性的影响

 吉林省长岭县羊草(Aneurolepidium chinense)草地自然保护区内分布的蚂蚁主要为玉米毛蚁(Lasius alienus)和黄墩蚁(Lasius flavus)。蚂蚁是草地生态系统的一个生物干扰因子。通过分析比较该保护区内4个植物群落中玉米毛蚁和黄墩蚁蚁丘上植物的种类组成、优势种的数量特征及群落多样性变化,探讨了蚂蚁筑丘活动对草地生态系统的影响。主要结论如下：1)蚁丘上的植物种类组成与对照显著不同。在蚁丘上分布的植物主要是羊草种组(Aneurolepidium chinense group     

松嫩平原盐碱植物群落种子库的比较分析

本文对松嫩平原碱化草甸6种单优盐碱植物群落土壤中有发芽力的种子贮量及其物种多样性进行了比较分析。虎尾草群落、角碱蓬群落、翅碱蓬群落3种一年生植物群落所具有的共同特征,表现为种子库存量大,优势种的种子数量占绝大多数,种子库的物种多样性指数相对较小。星星草群落和獐毛群落这两种过渡性的多年生群落,地上优势种均为种子库中的优势种,种子库的物种多样性指数趋于中等。羊草群落与其他演替阶段的群落相比,种子库存量最小,种子库的物种多样性指数最大。     

白龙江上游地区森林植物群落物种多样性的研究

 白龙江上游地区属长江防护林工程重点地区之一。根据36个样地的调查资料,分析了该地区森林植物群落物种多样性的特征：群落内各层物种丰富度指数的大小顺序为“灌木层>草本层>乔木层”;均匀度指数变化比较复杂,在杜鹃巴山冷杉（Rhododendron fastigiatum-Abies fargesii）林中为“草本层>灌木层>乔木层”,在苔藓巴山冷杉林中为“乔木层>灌木层>草本层”,其余群落中为“灌木层>草本层>乔木层”;多样性指数的大小顺序为“乔木层<灌木层和草本层”,而灌木层与草本层的多样性指数随林分郁闭度变化而变化,在郁闭度30%的杜鹃巴山冷杉林中,草本层大于灌木层,在郁闭度47%的箭竹巴山冷杉林中,草本层和灌木层相当,在郁闭度55%以上的各个群落内,灌木层大于草本层。同一海拔不同坡向群落的物种多样性表现为分布于阳坡的油松（Pinus tabulaeformis）林大于分布于阴坡的草类云杉（Picea asperata）林。物种多样性沿海拔梯度的变化表现为随海拔升高先降低后增加,从海拔2 400 m的栎类阔叶林,2 600 m的草类云杉林,2 800 m的箭竹(Sinarundinaria nitida)巴山冷杉林,到3 000 m的苔藓巴山冷杉林和3 200 m的杜鹃巴山冷杉林,物种多样性依次下降,到海拔3 400 m的高山杜鹃（Rhododendron fastigiatum）灌丛,物种多样性增加。物种多样性在紫果云杉(Picea purpurea)林的演替系列中表现为随群落演替发展而增加,后降低,在针阔混交林阶段达到最大。     

Within-community vegetation structure in the conifer woodlands of the Siskiyou Mountains,Oregon

The conifer woodlands found on serpentine-derived soils in southwest Oregon, USA, are characterized by a debse but discontinuous shrub stratum and a species-rich herbaceous stratum. Quantitative analysis of shrub and herb distributions within 10 sites showed that small-scale patterns within the conifer woodland sites are as important as landscape-scale patterns in community organization. Gradient analysis was used to describe the distribution of herbaceous species with respect to gradients of shrub influence (shading, decreased soil temperature, increased soil moisture, increased litter depth) within sites and topographic moisture among sites. Regression analysis of the resulting species distributions and calculations of alpha and beta diversity showed that (a) the shrub-influence microgradient significantly affected distributions for 15 out of 20 major herbaceous species, and the topographic-moisture gradient influenced 13 out of the 20 species, (b) species richness was higher under intermediate conditions along both gradients, and (c) beta diversity within communities was 2.5 to 3.8 times the beta diversity of the site-to-site topographic-moisture gradient.     

Diversity patterns of wet meadows along geochemical gradients in central Spain

Four measures of biodiversity (species number per site, total species number, mean similarity and mosaic diversity) and their relationships with soil chemical composition were studied in vascular plant communities in groundwater discharge ecosystems of central Spain. Species richness decreased with increasing salinity, alkalinity and halite concentration. Species richness was apparently controlled more by soil toxicity than by soil nutrient levels, although a positive correlation of Ca²⁺ with species richness was found after accounting for the effects of toxic compounds. All relationships were strictly monotonic. Six community types were identified based on their soil chemical characteristics: glycophyte, subglycophyte, tolerant, subalkalinophyte, alkalinophyte, and halocalcicole communities. Within community types, species richness showed very few significant relationships with soil characteristics. Mean species richness was lowest in the environmentally stressful communities. Total species richness was greatest in the ecotonal community type. Mean similarity, a measure of among-community diversity, and mosaic diversity, a measure of landscape complexity, differed among community types. Mean similarity was smaller (higher diversity) in species-poor community types, while mosaic diversity was greatest (greater complexity) in species-rich community types. The halocalcicole community type was richest in rare species.     

太白红杉群落物种多样性与环境因子的关系

定量研究了太白红杉群落物种多样性与环境因子的关系,结果表明:(1)海拔与物种丰富度和种间相遇机率呈极显著的负相关;与Shannon指数、Simpson指数和Pielou指数表现为"中间高度膨胀"的规律,即中等海拔高度上多样性高而低海拔和高海拔多样性较低。(2)岩石裸露度与物种丰富度呈显著的负相关。(3)土壤含水量与物种丰富度呈极显著的正相关;与种间相遇机率呈先降后升的趋势。(4)环境因子与物种多样性逐步回归结果是:海拔和岩石裸露度与物种丰富度关系密切,其回归方程为:S=90.62-0.02E-14.14B(r=0.769,P<0.05)。     

The vegetation of the Farasān Islands,Red Sea,Saudi Arabia

Abstract. Classification of the vegetation of the Farasān Islands using TWINSPAN technique resulted in the recognition of seven community types associated with seven different habitat types: silty runnels, palm orchards, rocky plains, rocky plateau crevices, coastal sand dunes, sand plains, and mangroves. These communities were dominated or co-dominated by 13 perennial species; 87 associate species were recorded in the study area with chamaephytes dominating the life-form spectrum. Canonical Correspondence Analysis (CCA) indicated that organic carbon, soil moisture, silt, electrical conductivity and calcium carbonate were the major edaphic gradients controlling the distribution of the plant communities on the Farasān Islands. Higher species richness was recorded in the plant communities inhabiting the palm orchards, the crevices of the rocky plateau, silty runnels, rocky plains and rocky plateau, while those of the mangrove and sand formations (dunes and plains) showed a lower species richness. Soil texture and organic matter are the main factors promoting species diversity in the more diversified habitats, while high salinity and calcium carbonate are the main factors associated with lower species diversity in the less diversified habitats of the study area.     

贵州部分森林群落物种多样性初步研究

 本文根据贵州省178个森林群落样地的数据研究了群落物种的多样性。测定的指标有群 落物种丰富度,群落Simpson多样性指数和群落均匀度。测定结果表明;不同垂直带生物气 候条件下的森林群落有不同的多样性。相同垂直带生物气候条件下,基质生境相同时,不同森林植被亚型的群落的多样性近似,基质生境不同时,群落多样性则不同;同一群落类型的各个样地的多样性也有变化,结构不同的群落个体,其多样性指数不同,演替趋势也不同。乔木第二亚层的多样性普遍地高于乔木第一亚层。同一演替系列中,越接近顶极阶段多样性越高。多样性指数与群落物种丰富度,均匀度呈紧密的正相关,与群落个体总数没有相关。认为多样性测定在比较、说明群落的结构、类型、组织特征、生境、演替等方面有一定意义。     

缙云山森林次生演替序列群落的物种多样性动态

通过１９８６ 和１９９６ 年对缙云山森林次生演替系列群落的重复调查,运用构成指数对这些群落进行演替排序,研究缙云山森林次生演替过程中的物种多样性动态．结果表明,构成指数（ ＣＩ） 可适当改变空间代替时间的局限;在缙云山森林次生演替过程中,物种丰富度呈先变大后变小的趋势,物种均匀度没有明显的动态规律,这与种间（ 内） 关系密切相关,因而适当干扰有利于群落内物种多样性的增大     

科尔沁沙地植被恢复系列上群落演替与物种多样性的恢复动态

通过对科尔沁沙地植被恢复系列上不同阶段的群落取样,研究了植被恢复过程中群落物种组成、物种多样性的变化过程.在演替时间分别为1年、3年、5年、12年、20年和30年的群落中,物种丰富度分别为7、11、17、14、28和30种,而物种多样性指数分别为1.458 8、2.610 0、3.108 4、1.696 8、3.738 6、3.639 6.在生活型结构上,一年生植物的种类数量占绝对优势,但随着演替进展,多年生植物的种类数量增加且单种植物的优势度超过了一年生植物,表明多年生植物在群落功能维持中占据重要地位.随演替进展,来自不同科属的植物增加.藜科植物在演替过程中种类数量较为稳定,特别是在演替早期藜科植物占有很高的优势度.禾本科种类随演替进展不断增加,且在群落中的优势度逐渐上升.总体上,随演替进展群落种类组成与物种多样性增加,群落生态优势度下降,而均匀度增加,群落趋向稳定.     

太行山干瘠山地土壤厚度空间变异及草灌群落分布特征

在自然条件下,太行山低山区干瘠山地土层浅薄,易形成一定的裸地斑块造成水土流失等灾害,天然林覆盖率低,植被丰富度、物种多样性也受到限制。为探讨土壤厚度与植物群落分布特征的关系,选择太行山低山区干瘠山地东北向和西南向2个坡面,运用地统计学方法研究了土壤厚度的空间变异特征,比较了不同土壤厚度下群落分布、物种多样性和物种丰富度的差异。研究表明:1)东北向和西南向2个坡面的土壤厚度在0—50 cm间,平均厚度分别为11.69 cm和12.77 cm;在0—15 cm的土壤厚度分别占总数的71.43%和62.81%。2)东北向和西南向2坡面土壤厚度呈斑块状分布,但具有显著的空间异质性和强烈的空间相关性,属于中等偏强空间变异,结构性因素是造成土壤厚度空间变异的主导因子。3)所选取坡面的植物主要以草灌为主,共有22科33属38种。土层厚度在10 cm以下时,植物以草本为主;土层厚度在10 cm以上时,植物以灌木为主。其中,土层厚度在10—20 cm时,胡枝子为优势种;土层厚度在20 cm以上时,荆条、酸枣为优势种。4)随着土壤厚度的增加,植物群落组成发生显著变化,在土壤厚度小于15 cm时,物种多样性和物种丰富度随着土壤厚度逐渐增加,在土壤厚度为10—15 cm时达到最大,在土壤厚度大于15 cm时,随着土壤厚度的增加物种多样性和物种丰富度逐渐降低,说明土壤厚度影响植物多样性和物种丰富度。     

Realistic Variation in Species Composition Affects Grassland Production,Resource Use and Invasion Resistance

We investigated the effects of realistic variation in plant species and functional group composition, with species occurring at realistic abundances, on ecosystem processes in exotic-dominated California grassland communities. Progressive species removals from microcosm communities, designed to mimic nested variation in diversity observed in the field, reduced grassland production, resistance to intentional invasions, and resistance to natural colonization by new species. Three lines of evidence point to the particular importance of intensified competition within a single functional group—late-active forbs—in explaining the observed effects of realistic species loss order on community resistance. First, reduced success of naturally colonizing species in more diverse assemblages was dominated by declining colonization by late-active forbs. Second, increasing late-active forb biomass appeared to reduce the biomass of intentionally introduced yellow starthistle (Centaurea solstitialis, a late-season forb) both within and across diversity levels. Finally, starthistle addition reduced biomass of resident late-season forbs but not of any other functional group. Increasing diversity increased light levels and soil moisture availability in spring and summer, providing a proximate mechanism linking our realistic species loss order to decreased community resistance. Starthistle addition reduced light and soil moisture availability but not N across richness levels, mirroring the apparent effects of the additional late-active forb species present in higher diversity treatments. Species losses that entail the early loss of whole or key functional groups could, through mechanisms like those we explore, have greater ecosystem consequences than those suggested by randomized-loss experiments.     

Isolated and combined impacts of blue mussels (Mytilus edulis) and barnacles (Balanus improvisus) on structure and diversity of a fouling community

Effects of two presumably dominant competitors, the blue mussel Mytilus edulis and the barnacle Balanus improvisus on recruitment, population dynamics and community structure on hard substrata were experimentally investigated in the subtidal Kiel Fjord, Western Baltic. The hypothesis that blue mussels and/or barnacles are local dominants and strongly influence succession and community structure was tested by monitoring succession in the presence and absence of simulated predation on either or both species. Manipulations included blue mussel removal, barnacle removal, combined blue mussel and barnacle removal, as well as a control treatment for natural (non-manipulated) succession. In the second part of the experiment, recovery from the treatments was monitored over 1 year.During the manipulative phase of the experiment, blue mussels had a negative effect on recruitment of species, whereas barnacles had no significant effect. Even so, a negative synergistic effect of blue mussels and barnacles was detected. Calculation of species richness and diversity H′ (Shannon Index) showed a negative synergistic effect of blue mussels and barnacles on community structure. Additionally, diversity H′ was negatively affected by the dominant competitor M. edulis. These effects were also detectable in the ANOSIM-Analysis. The non-manipulative phase of the experiment brought about a drastic loss of diversity and species richness. Blue mussels dominated all four communities. Barnacles were the only other species still being able to coexist with mussels. Effects of simulated predation disappeared fast.Thus, in the absence of predation on blue mussels, M. edulis within a few months dominates available space, and diversity of the benthic community is low. In contrast, when mussel dominance is controlled by specific predators, more species may persist and diversity remains high.     

安太堡矿区复垦地植被种间关系及土壤因子分析

为研究安太堡矿区植被复垦过程中不同植物群落类型的种间关系及影响群落稳定性的外部环境因子, 作者对矿区的植物群落和自然生境进行了野外调查。对森林、灌丛和草地3种群落分别在10 m×10 m、 4 m×4 m和1 m×1 m的尺度上, 采用校正的χ2检验、Spearman秩相关分析研究了不同群落类型中出现频率较高的物种之间的联结性, 同时应用灰色关联识别对影响群落稳定性的土壤因子进行了识别。结果表明: 草地群落中物种组成贫乏, 以旱生种为优势类群, 物种间既具有一定的联结性, 又具有相当独立的分布格局。灌丛群落主要种整体呈现正联结, 其组成成分仍以旱生或中旱生物种为主, 部分中生性物种的出现及其与优势种的正相关关系都在一定程度上指示了灌丛群落向正向演替方向进行。森林群落主要种也整体呈现正联结, 表明群落处于植被演替进程中一个相对稳定的过渡阶段。土壤因子与植物群落稳定性的关联顺序为: 有机质> N > P> K> Cu> Mn > pH > Zn>电导率。总的来看, 矿区现有森林群落配置方式是较灌丛群落和草地群落配置方式更适合于矿区特殊生境的群落类型, 而土壤因子中有机质在决定群落稳定性方面发挥重要作用。此研究结果对制定该矿区植被恢复计划具有参考价值。     

Changes in biotic and abiotic drivers of seedling species composition during forest recovery following shifting cultivation on Hainan Island,China

Seedlings play an important role in the processes of plant community succession. We compared seedling (dbh < 1 cm) species composition and diversity over a chronosequence (18‐, 30‐, 60‐year‐old second growth and old growth forest) after shifting cultivation in a tropical lowland rain forest area on Hainan Island, China. Seedling diversity reached a maximum in the 60‐year‐old second growth forest, which is consistent with the intermediate disturbance hypothesis. With the progression of secondary succession, canopy openness (CO), soil organic matter, soil phosphorus content, and tree abundance showed a general decreasing trend; soil water content and tree basal area showed a general trend of increase, while soil pH and other nutrients reached maximum values and tree richness reached a minimum value at intermediate stages of succession. Seedling composition and diversity were significantly affected by soil water, pH, soil nutrient content, and biotic factors in the 18‐year‐old second growth forests; by soil pH, soil nutrient content, and biotic factors in the 30‐year‐old second growth forests; by CO, soil nutrient content and tree abundance in the 60‐year‐old second growth forests; and by CO, soil pH, and soil nutrient content in the old growth forests. At earlier stages of succession, the effect of the proportion of old growth forest in the surrounding landscape on seedling diversity was greater than that of land‐use history, but the importance of these drivers was reversed at later stages of succession.     

Effects of cover soil stockpiling on plant community development following reclamation of oil sands sites in Alberta

Stockpiling of cover soil can influence vegetation development following reclamation. Cover soil, comprising the upper 15–30 cm of the surface material on sites scheduled for mining, is commonly salvaged prior to mining and used directly or stockpiled for various lengths of time until it is needed. Salvaging and stockpiling causes physical, chemical, and biological changes in cover soils. In particular, stockpiling reduces the availability and vigor of vegetative propagules and seed, and can lead to increases in the abundance of some weedy species. This study uses data from monitoring plots to assess how stockpiling of cover soil impacts plant community development on reclaimed oil sands mine sites in northern Alberta. Development of plant communities differed distinctly between directly placed and stockpiled cover soil treatments even 18 years after reclamation. Direct placement of cover soil resulted in higher percent cover, species richness, and diversity. Nonmetric multidimensional scaling and multiresponse permutation procedure revealed compositional differentiation between the treatments. Indicator species analysis showed that direct placement treatment was dominated by perennial species while grasses and annual forb species dominated sites where stockpiled soil was used. Results indicate that stockpiling leads to slower vegetation recovery while direct placement of cover soil supports more rapid succession (from ruderal and annual communities to perennial communities). In addition, direct placement may be less costly than stockpiling. However, scheduling of salvage and placement remains a challenge.     

广西阳朔岩溶植被演替过程种群变化及物种多样性

采用时空替代法研究广西阳朔岩溶植被在演替过程中的种群变化和物种多样性。研究表明,随着演替的进展,耐荫种群增加,乔木种群增加,优势种的更替呈现出一定的连续性,后一演替阶段的优势种往往已经隐含在前一演替阶段中;物种丰富度随演替进展表现出草丛<落叶阔叶林<灌丛<常绿落叶阔叶混交林的趋势;灌木层的物种丰富度在各演替阶段中均是最高的;在各演替阶段中,落叶阔叶林阶段的群落均匀度均表现为最大。